Process and apparatus for producing a golf ball with deep dimples

ABSTRACT

An apparatus and related techniques for making a golf ball with deep dimples are disclosed. The golf ball comprises a core and a cover layer, wherein the cover layer provides deep dimples that extend through the cover layer and/or into a layer or component underneath are disclosed. At least one percent (1%), preferably about five percent (5%), of the dimples of the ball comprise deep dimples. The cover may be a single layer or include multiple layers. If the cover is a multi-layer cover, the dimples extend to or into at least the first inner cover layer, and may extend to or into two or more inner cover layers. If the cover is a single layer, the dimples extend to or into the core. The dimples may be spherical or nonspherical, and the portion of the dimple that extends to or into the next inner layer may be the same or different shape as the outer portion of the dimple.

CROSS REFERENCES TO RELATED APPLICATIONS

[0001] The present application claims priority upon U.S. ProvisionalApplication Serial No. 60/337,123, filed Dec. 4, 2001; U.S. ProvisionalApplication Serial No. 60/356,400, filed Feb. 11, 2002; and U.S.Provisional Application Serial No. , filed Oct. 30, 2002.

FIELD OF THE INVENTION FIELD OF THE INVENTION

[0002] The present invention pertains to the art of making golf balls,and, more particularly, to golf balls having deep dimples. The presentinvention also relates to processes and apparatuses for formingmulti-layer golf balls, and more particularly to processes and equipmentfor forming multi-layer golf balls having several deep dimples thatextend through the outer cover layer to and/or into one or more layersor components thereunder.

BACKGROUND OF THE INVENTION

[0003] Golf balls are typically made by molding a core of elastomeric orpolymeric material into a spheroid shape. A cover is then molded aroundthe core. Sometimes, before the cover is molded about the core, anintermediate layer is molded about the core and the cover is then moldedaround the intermediate layer. The molding processes used for the coverand the intermediate layer are similar and usually involve eithercompression molding or injection molding.

[0004] In compression molding, the golf ball core is inserted into acentral area of a two piece die and pre-sized sections of cover materialare placed in each half of the die, which then clamps shut. Theapplication of heat and pressure molds the cover material about thecore.

[0005] Blends of polymeric materials have been used for modern golf ballcovers because certain grades and combinations have offered certainlevels of hardness to resist damage when the ball is hit with a club andelasticity to allow responsiveness to the hit. Some of these materialsfacilitate processing by compression molding, yet disadvantages havearisen. These disadvantages include the presence of seams in the cover,which occur where the pre-sized sections of cover material were joined,and long process cycle times which are required to heat the covermaterial and complete the molding process.

[0006] Injection molding of golf ball covers arose as a processingtechnique to overcome some of the disadvantages of compression molding.The process involves inserting a golf ball core into a die, closing thedie and forcing a heated, viscous polymeric material into the die. Thematerial is then cooled and the golf ball is removed from the die.Injection molding is well-suited for thermoplastic materials, but haslimited application to some thermosetting polymers. However, certaintypes of these thermosetting polymers often exhibit the hardness andelasticity desired for a golf ball cover. Some of the most promisingthermosetting materials are reactive, requiring two or more componentsto be mixed and rapidly transferred into a die before a polymerizationreaction is complete. As a result, traditional injection moldingtechniques do not provide proper processing when applied to thesematerials.

[0007] Reaction injection molding is a processing technique usedspecifically for certain reactive thermosetting plastics. As mentionedabove, by “reactive” it is meant that the polymer is formed from two ormore components which react. Generally, the components, prior toreacting, exhibit relatively low viscosities. The low viscosities of thecomponents allow the use of lower temperatures and pressures than thoseutilized in traditional injection molding. In reaction injectionmolding, the two or more components are combined and reacted to producethe final polymerized material. Mixing of these separate components iscritical, a distinct difference from traditional injection molding.

[0008] The process of reaction injection molding a golf ball coverinvolves placing a golf ball core into a die, closing the die, injectingthe reactive components into a mixing chamber where they combine, andtransferring the combined material into the die. The mixing begins thepolymerization reaction which is typically completed upon cooling of thecover material.

[0009] The present invention provides a new mold or die configurationand a new method of processing for reaction injection molding a golfball cover or inner layer which promotes increased mixing of constituentmaterials, resulting in enhanced properties and the ability to explorethe use of materials new to the golf ball art.

[0010] For certain applications it is desirable to produce a golf ballhaving a very thin cover layer. However, due to equipment limitations,it is often very difficult to mold a thin cover. Accordingly, it wouldbe beneficial to provide an apparatus and technique for producing arelatively thin cover layer.

[0011] Moreover, retractable pins have been utilized to hold, or center,the core or core and mantle and/or cover layer(s) in place within aninjection mold while molding an outer cover layer thereon. In suchprocesses, the core or mantled ball is supported in the mold usingretractable pins extending from the inner surface of the mold to theouter surface of the core or mantled ball. The pins in essence supportthe core or mantled ball while the cover layer is injected into themold. Subsequently, the pins are retracted as the cover material fillsthe void between the core or mantle and the inner surface of the mold.

[0012] However, notwithstanding, the benefits produced through the useof the retractable pins, the pins sometimes produce centeringdifficulties and cosmetic problems (i.e. pin flash, pin marks, etc.)during retraction, which in turn require additional handling to producea golf ball suitable for use and sale. Additionally, the lower theviscosity of the mantle and/or cover materials, the greater the tendencyfor the retractable pins to stick due to material accumulation, makingit necessary to shut down and clean the molds routinely. Accordingly, itwould be desirable to provide an apparatus and method for forming acover layer on a golf ball without the use of retractable pins.

SUMMARY OF THE INVENTION SUMMARY OF THE INVENTION

[0013] The present invention provides, in a first aspect, a golf ballhaving a plurality of deep dimples defined along an outer surface of thegolf ball. The golf ball comprises a core and a cover layer disposedabout the core. The cover layer has an outer surface and a thickness anddefines a collection of dimples along its outer surface. At least 1%,and more preferably at least 5%, of the dimples have a depth greaterthan the thickness of the cover layer, and thus extend through the coverlayer.

[0014] In another aspect, the present invention provides a golf ballcomprising a core and a cover layer disposed about the core. The coverlayer has a thickness and defines at least two populations of dimplesalong an outer surface of the cover layer. A first population of dimplesincludes dimples having a depth greater than the thickness of the coverlayer. The second population of dimples includes dimples having a depthless than the thickness of the cover layer. The first population ofdimples constitutes at least a minority proportion of the total numberof dimples defined along the outer surface of the cover layer.

[0015] In yet another aspect, the present invention provides a moldingapparatus for forming a golf ball having a cover with a thickness and aplurality of dimples along its outer surface. The molding apparatuscomprises a first molding component that defines a hemispherical firstmold surface. The first mold surface has at least two populations ofoutwardly extending projections that form dimples. The populationsdiffer from each other by the height of the projections. The moldingapparatus also comprises a second molding component that defines ahemispherical second mold surface. The second mold surface has at leasttwo populations of outwardly extending projections that form the noteddimples. The populations differ from each other by the height of theprojections. The second molding component is adapted such that, uponengagement with the first molding component, a generally sphericalmolding chamber results from the first mold surface and the second moldsurface. The molding apparatus also comprises provisions for receivingone or more flowable materials used for forming the golf ball andadministering such materials into the molding chamber. At least onepopulation of the outwardly extending projections of the first moldsurface and at least one population of outwardly extending projectionsof the second mold surface have a projection height in the range of fromabout 0.005 inches to about 0.050 inches.

[0016] In a further aspect, the present invention provides a reactioninjection molding apparatus for forming a golf ball core or intermediateball assembly and an outer cover layer disposed about the core or ballassembly. The molding apparatus comprises a first mold defining ahemispherical first mold surface. The molding apparatus also comprises asecond mold defining a hemispherical second mold surface. The first andsecond mold surfaces have a first population of raised regions that formdimples along the cover layer of the golf ball. The first and secondmold surfaces also have a second population of raised regions eachhaving a height greater than the thickness of the cover layer of theball. The molding apparatus also comprises provisions for receiving twoor more flowable reactants utilized for forming the outer cover layer.The second population of raised regions constitutes a minorityproportion of the total number of dimples along the cover layer.

[0017] In yet another aspect, the present invention provides a processfor producing a golf ball having a particular proportion of deep dimplesalong an outer surface of the ball. The process comprises providing amolding apparatus that defines a generally spherical molding chamberresulting from a molding surface having a first population of raisedregions that form dimples in the golf ball, and a second population ofraised regions that form deep dimples in the golf ball. The process alsocomprises a step of providing a flowable molding material to the moldingapparatus. The process includes another step of positioning a core orintermediate ball assembly in the molding chamber. The process includesa further step of introducing the flowable molding material into themolding chamber between the core or intermediate ball assembly and themolding surface. The process comprises another step of hardening theflowable material to thereby form the golf ball. The second populationof the raised regions constitutes at least 5% of the total number ofdimples along the outer surface of the ball.

[0018] A further aspect of the invention is to provide equipment andmethods for forming a golf ball having a dimpled cover that is thinnerthan traditional cover layers.

[0019] Another aspect of the invention is to provide equipment andmethods for forming a golf ball having a plurality of dimples in anouter cover layer that extend to, and/or into, at least the next innerlayer of the ball.

[0020] Still further advantages of the present invention will becomeapparent to those of ordinary skill in the art upon reading andunderstanding the following detailed description of the preferredembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following figures are not necessarily to scale, but aremerely illustrative of the present invention. Specifically, the figuresare for purposes of illustrating various aspects and preferredembodiments of the present invention and are not to be construed aslimiting the invention described herein.

[0022]FIG. 1 is a perspective view revealing the components of apreferred embodiment golf ball in accordance with the present invention.

[0023]FIG. 2 is a perspective view of a preferred embodiment moldingassembly in accordance with the present invention.

[0024]FIG. 3 is a planar view of a portion of the preferred embodimentmolding assembly taken in the direction of line 3-3 in FIG. 2.

[0025]FIG. 4 is a planar view of a portion of the preferred embodimentmolding assembly taken in the direction of line 44 in FIG. 2.

[0026]FIG. 5 is a detailed perspective view of a portion of thepreferred embodiment molding assembly taken in the direction of line 5-5in FIG. 2. This view illustrates a mix-promoting peanut after-mixer inaccordance with the present invention.

[0027]FIG. 6 is a detailed view of the peanut after-mixer of thepreferred embodiment molding assembly in accordance with the presentinvention.

[0028]FIG. 7 is a planar view of a portion of an alternative embodimentof the molding assembly in accordance with the present invention.

[0029]FIG. 8 is a planar view of a portion of an alternative embodimentof the molding assembly in accordance with the present invention.

[0030]FIG. 9 is a planar view of a portion of an alternative embodimentof the molding assembly in accordance with the present invention.

[0031]FIG. 10 is a flow chart illustrating a preferred embodimentprocess in accordance with the present invention.

[0032]FIG. 11 is a cross-sectional view of another preferred embodimentgolf ball according to the present invention having a core and a singlecover layer having dimples, wherein one or more of the dimples extendsthrough the cover to and/or into the underlying core.

[0033]FIG. 12 is a diametrical cross-sectional view of the preferredembodiment golf ball illustrated in FIG. 11.

[0034]FIG. 13 is a cross-sectional view of another preferred embodimentgolf ball according to the present invention having a core component anda cover component, wherein the cover component includes an inner coverlayer and an outer cover layer having dimples formed therein, andwherein one or more of the dimples of the outer cover layer extends toand/or into the underlying inner cover layer.

[0035]FIG. 14 is a diametrical cross-sectional view of the preferredembodiment golf ball illustrated in FIG. 13.

[0036]FIG. 15 is a cross-sectional detail view of a portion of anotherpreferred embodiment golf ball according to the present invention havinga core and a cover illustrating a dual radius dimple that extendsthrough the cover into the underlying core.

[0037]FIG. 16 is a cross-sectional detail view of a portion of anotherpreferred embodiment golf ball according to the present invention havinga core and a cover illustrating a dual radius dimple that extendsthrough the outer cover layer to the outer surface of the core.

[0038]FIG. 17 is a cross-sectional detail view of a portion of anotherpreferred embodiment golf ball according to the present invention havinga core, an inner cover layer, and an outer cover layer, wherein theouter cover layer has a dual radius dimple that extends into the innercover layer.

[0039]FIG. 18 is a cross-sectional detail view of a portion of anotherpreferred embodiment golf ball according to the present invention havinga core, an inner cover layer, and an outer cover layer illustrating adual radius dimple that extends through the outer cover layer to theinner cover layer of the ball.

[0040]FIG. 19 is a schematic view of a preferred embodiment moldingassembly and a golf ball core according to the present invention.

[0041]FIG. 20 is a process flow diagram which schematically depicts areaction injection molding process according to the invention.

[0042]FIG. 21 schematically shows a preferred embodiment moldingassembly for reaction injection molding a golf ball cover according tothe invention.

[0043]FIG. 22 is a schematic process flow diagram illustrating a heatexchange circuit utilized for an isocyanate feed source.

[0044]FIG. 23 is a schematic process flow diagram illustrating a heatexchange circuit utilized for a polyol feed source.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] The present invention relates to equipment and methods forproducing improved golf balls, particularly a golf ball comprising acover disposed about a core in which the cover has one or more,preferably a plurality of, deep dimples or apertures that extend throughthe outer cover to and/or into one or more layers underneath.

[0046] The present invention also relates to equipment and methods forproducing golf ball assemblies, i.e. cores having one or more mantle orinner cover layers disposed thereon, in which the core or ball assemblyincludes a plurality of deep dimples. The golf balls of the presentinvention, which can be of a standard or enlarged size, have a uniquecombination of cover thickness and dimple configuration. The presentinvention also relates to forming these golf balls, or at least certaincomponents thereof, by reaction injection molding techniques. Such deepdimples extend through at least one cover layer to, and/or into, theunderlying surface or component or layer.

[0047] With regard to dimple configuration or cross-sectional geometry,the present invention is based upon the identification of variousparticularly preferred characteristics as follows. Typically, forcircular dimples, dimple diameter is used in characterizing dimple sizerather than dimple circumference. The diameter of typical dimples mayrange from about 0.050 inches to about 0.250 inches. A preferreddiameter of a typical dimple is about 0.150 inches. The deep dimples mayhave these same dimensions or may have dimensions as described ingreater detail herein. As will be appreciated, circumference of a dimplecan be calculated by multiplying the diameter times p.

[0048] The depth of typical dimples previously utilized in the trade mayrange from about 0.002 inches to about 0.020 inches or as much as 0.050inches. Preferably, a depth of about 0.010 inches is preferred fortypical or conventional dimples. It is preferred that the depth of adeep dimple as described herein is greater than the depth of a typicaldimple. Most preferably, the deep dimples have a depth that is deeperthan the depth of the typical dimples by at least 0.002 inches.

[0049] Specifically, depth of a dimple may be defined in at least twofashions. A first approach is to extend a chord from one side of adimple to another side and then measure the maximum distance from thatchord to the bottom of the dimple. This is referred to herein as a“chordal depth.” Alternatively, another approach is to extend animaginary line corresponding to the curvature of the outer surface ofthe ball over the dimple whose depth is to be measured. This is referredto herein as a “periphery depth.” The latter format of dimple depthdetermination is used herein unless noted otherwise.

[0050] As described herein, the deep dimples included in the presentinvention are particularly useful when molding certain layers orcomponents about cores or intermediate ball assemblies. The depth of adeep dimple as described herein may range from about 0.002 inches toabout 0.140 inches, more preferably from about 0.002 inches to about0.050 inches, and more preferably from about 0.005 inches to about 0.040inches. Preferably, a total depth of about 0.025 inches is desired. Itis most preferred that the depth of a deep dimple as described herein isgreater than the depth of a typical dimple and extend to at least theoutermost region of the mantle or core. Alternatively, the deep dimplespreferably extend to the bottom of a matched set of dimples on themantle or the core. The diameter of the deep dimples may be dissimilar,but preferably is the same as other dimples on a ball, and may rangefrom about 0.025 inches to about 0.250 inches and more preferably fromabout 0.050 inches to about 0.200 inches. A preferred diameter is about0.150 inches. Generally, depth is measured from the outer surface of afinished ball, unless stated otherwise.

[0051] In one embodiment, the present invention relates to an apparatusand technique for forming a golf ball comprising a core and a coverlayer, wherein the cover layer provides dimples including one or moredeep dimples that extend to or into the next inner layer or component.The cover may be a single layer or comprise multiple layers, such astwo, three, four, five or more layers and the like. If the cover is amulti-layer cover, the dimples extend into at least the first innercover layer, and may extend into a further inner cover layer, a mantleor intermediate layer, and/or the core. If the cover is a single layer,the deep dimples may extend into a mantle layer and/or the core. Thecover layer(s) may be formed from any material suitable for use as acover, including, but not limited to, ionomers, non-ionomers and blendsof ionomers and non-ionomers.

[0052] In another embodiment, the present invention relates to anapparatus and technique for forming a golf ball comprising a core and acover layer, wherein the cover layer provides dimples that extend to thecore. The golf ball may optionally comprise a thin barrier coatingbetween the core and the cover that limits the transition of moisture tothe core. The barrier coating is preferably at least about 0.0001 inchesthick. Preferably, the barrier layer is at least 0.003 inches thick. Ina two-piece golf ball, a barrier coating is preferably provided betweenthe core and the cover.

[0053] In a further embodiment, the present invention relates toequipment and processes for forming a golf ball having a plurality ofdimples along its outer surface. In accordance with the presentinvention, one or more of these dimples are deep dimples that extendentirely through the cover layer of the ball, and to or into one or moreunderlying components or layers of the ball. For instance, for a golfball comprising a core and a cover layer disposed about the core, thedeep dimples preferably extend through the cover layer and to or intothe core. If one or more layers such as an intermediate mantle layer areprovided between the core and the cover layer, the deep dimplespreferably extend through the cover layer and to or into one or more ofthose layers. The deep dimples may additionally extend into the core.

[0054] The deep dimples of the present invention may be spherical ornonspherical. Additionally, the portion of the deep dimple that extendsto, or into the next inner layer or component may be the same ordifferent size and/or shape as the outer portion of the dimple.

[0055] Turning now to the drawings, with reference to FIG. 1, apreferred embodiment golf ball 10 in accordance with the presentinvention is illustrated. The golf ball 10 includes a central core 12which may be solid or liquid as known in the art. A cover 14 issurroundingly disposed about the central core 12. An intermediate layer16 may be present between the central core 12 and the cover 14. Thepresent invention primarily relates to the cover 14 and will bedescribed with particular reference thereto, but it is also contemplatedto apply to molding of the intermediate layer 16. The preferredembodiment ball 10 includes one or more deep dimples 18 that extendthrough at least the cover layer 14. The deep dimples 18 extend to, orthrough, the intermediate layer 16. The deep dimples may further extendinto the core 12. It will be appreciated that in the event the core isliquid, the deep dimples will not extend to the core.

[0056] As noted, the present invention relates to various moldingassemblies and techniques for forming a golf ball having one or moredeep dimples along an outer surface of the golf ball. The deep dimplesextend through the outermost cover layer of the ball, to or into orthrough one or more components underneath the outermost cover layer. Asexplained herein, the deep dimples result from one or more outwardlyextending projections or protrusions that are provided in a moldingchamber used for molding the final ball. The protrusions generally havea height greater than other raised regions along the molding surfacethat form conventional dimples along the ball exterior.

[0057] Turning now to FIG. 2, a perspective view of a preferredembodiment molding assembly in accordance with the current invention isshown. As previously noted, complete and timely mixing of two or moreconstituent materials is important when using a RIM process. Thepreferred embodiment molding assembly 20 provides such mixing as aresult of its unique design and configuration. An injection machine, asknown in the art, is connected to the preferred embodiment moldingassembly 20 which comprises an upper half 22A and a lower half 22B. Aswill be appreciated, the upper and lower halves 22A and 22B arepreferably formed from a metal or suitable material. A mixing chambermay, as known in the art, precede the molding assembly 20 if desired. Ina further aspect of the present invention, the molding assembly 20 isutilized as follows. A core 12 (referring to FIG. 1) is positionedwithin a central cavity formed from two hemispherical depressions 24Aand 24B defined in opposing faces of the upper half and lower half 22Aand 22B, respectively, of the molding assembly 20. As will beappreciated, when the upper and lower halves 22A and 22B are closed, andthe cavities 24A and 24B are aligned with each other, the resultingcavity has a spherical configuration. If the molding assembly is formolding a cover layer, each of the hemispherical cavities 24A and 24Bdefines a plurality of raised regions that, upon molding a cover layertherein, will result in corresponding dimples on the cover layer.

[0058] Each upper and lower half 22A and 22B of the preferred embodimentmolding assembly 20 defines an adapter portion 26A and 26B to enable themolding assembly 20 to connect to other process equipment as mentionedabove and leads to a material inlet channel 28A and 28B as illustratedin FIG. 2. As will be understood, upon closing the upper and lowerhalves 22A and 22B of the molding assembly 20, the separate halves ofadapter portion 26A and 26B are aligned with each other and create amaterial flow inlet within the molding assembly. And, each upper andlower half 22A and 22B of the assembly 20 further defines flow channels28A and 28B, 30A and 30B and 32A and 32B which create a comprehensiveflow channel within the molding assembly when the upper and lower halves22A and 22B are closed. Specifically, the material flow inlet channelportion 28A, 28B receives the constituent materials from the adapterportion 26A and 26B and directs those materials to aturbulence-promoting portion of the channel 30A, 30B which is configuredto form at least one fan gate. The upper and lower mold halves 22A and22B include complimentary turbulence-promoting peanut after-mixerchannel portions 30A and 30B, respectively. It will be appreciated thatupon closing the upper and lower halves 22A and 22B of the moldingassembly 20, the channel portion 30A and 30B defines a region of theflow channel that is generally nonlinear and includes a plurality ofbends and at least one branching intersection generally referred toherein as an after-mixer gate. Each after-mixer channel portion 30A, 30Bis designed to direct material flow along an angular or tortuous path.As will be described in more detail below, when material reaches aterminus of angular flow in one plane of the flow channel in one half,the material flows in a transverse manner to a corresponding after-mixerchannel portion in the opposing half. Thus, when the constituentmaterials arrive at the after-mixer defined by the channel portion 30Aand 30B, turbulent flow is promoted, forcing the materials to continueto mix within the molding assembly 20. This mixing within the moldingassembly 20 provides for improved overall mixing of the constituentmaterials, thereby resulting in a more uniform and homogeneouscomposition for the cover 14.

[0059] With continuing reference to FIGS. 3 and 4, views 3-3 and 4-4from FIG. 2, respectively, are provided. These views illustrateadditional details of the present invention as embodied in the moldupper and lower halves 22A and 22B. The material inlet channel 28A and28B allows entry of the constituents which are subsequently directedthrough the mix-promoting channel portion 30A and 30B, which forms theafter-mixer, then through the connecting channel portion 32A and 32B andto the fan gate portion 34A and 34B which leads into the cavity 24A and24B. The final channel portion 34A and 34B may be defined in severalforms extending to the cavity 24A and 24B, including corresponding orcomplimentary paths which may be closed (34A) or open (34B) and ofstraight, curved or angular (34A, 34B) shape.

[0060] With continuing reference to FIGS. 3 and 4, at least oneprotrusion 36 preferably extends into the central cavity 24A and 24B.This at least one protrusion extends from the molding surface into themolding cavity 24A and 24B and supports a golf ball core, such as core12, or intermediate ball assembly. The preferred dimensions,configuration, and orientation of the protrusion(s) are explained ingreater detail herein. It is these protrusion(s) that form one or moredeep dimple(s) in the outer surface of a golf ball and which relate toanother aspect of the present invention. In typical injection molding,many retractable pins, often four, six or more, are used to centrallyposition and retain the core 12 in the molding cavity. It has beendiscovered that because of the reduced process pressure involved in RIM,fewer supporting structures are necessary in the molding assembly 20 tocentrally locate the core 12 in the central cavity 24A and 24B. Forexample, only three protrusions 36 or less may be necessary per moldhalf. For some embodiments, it is preferred to utilize six protrusionsper mold half. The use of fewer supporting structures reduces the costof the tooling and reduces problems such as defacement and surfaceimperfections caused by retractable pins. The protrusions 36 arepreferably provided at different locations in the molding assembly 20and extend into different portions of the central cavity formed by thehemispherical cavities 24A, 24B. A channel leading from the cavity 24Aand 24B may be provided as either a cavity venting channel or anoverflow channel or dump well as known in the art. As shown in FIG. 2, adump well 31A, 31B is provided in the corresponding molds. A dump wellvent 33A, 33B provides communication between the dump well and moldexterior. A venting channel 29A, 29B is defined in the molds andprovides communication between the central cavity 24A, 24B and the dumpwell. It will be appreciated that when the upper and lower halves 22Aand 22B are closed, the respective portions of the channel align withone another to form the venting or overflow channel.

[0061] Turning now to FIG. 5, a perspective view of the molding assembly20 illustrates the details of material flow and mixing provided by thecurrent invention. The body halves 22A and 22B are shown in an openposition, i.e., removed from one another, for purposes of illustrationonly. It will be appreciated that the material flow described belowtakes place when the halves 22A and 22B are closed. The adapter portion26A, 26B leads to the inlet flow channel 28A, 28B which typically has auniform circular cross section of 360°. The flowing material proceedsalong the inlet channel 28A, 28B until it arrives in a locationapproximately at a plane designated by line C-C. At this region, thematerial is forced to split apart by a branching intersection 38A and38B. Each half of the branching intersection 38A and 38B is divergent,extending in a direction generally opposing the other half. For example,portion 38A extends upward and 38B extends downward relative to theinlet channel 28A, 28B as shown. Each half of the branching intersection38A and 38B, in the illustrated embodiment, is semicircular, or about180° in curvature. The separated material flows along each half of thebranching intersection 38A and 38B until it reaches a respective wall,40A and 40B.

[0062] At each first wall 40A and 40B, the material can no longercontinue to flow within the plane of the closed mold, i.e., the halves22A and 22B being aligned with one another. To aid the presentdescription it will be understood that in closing the mold, the upperhalf 22A is oriented downward (referring to FIG. 5) so that it isgenerally parallel with the lower half 22B. The orientation of thehalves 22A and 22B in such a closed configuration is referred to hereinas lying in an x-y plane. As explained in greater detail herein, theconfiguration of the present invention after-mixer provides one or moreflow regions that are transversely oriented to the x-y plane of theclosed mold. Hence, these transverse regions are referred to asextending in a z direction.

[0063] Specifically, at the first wall 40A the material flows from apoint 1 in one half 22A to a corresponding point 1 in the other half22B. Point 1 in half 22B lies at the commencement of a first convergentportion 42B. Likewise, at the first wall 40B the material flows from apoint 1 in one half 22B to a corresponding point 1 in the other half22A. The point 1 in half 22A lies at the commencement of a firstconvergent portion 42A. The first convergent portion 42A and 42B bringsthe material to a first common area 44A and 44B. In the shownembodiment, each first convergent portion is parallel to each firstdiverging branching intersection to promote a smooth material transfer.For example, the portion 42A is parallel to the portion 38A, and theportion 42B is parallel to the portion 38B.

[0064] With continuing reference to FIG. 5, the flowing material arrivesat the first common area 44A and 44B, which has a full circular, i.e.,360 degrees, cross section when the halves 22A and 22B are closed.Essentially, the previously separated material is rejoined in the firstcommon area 44A and 44B. A second branching intersection 46A and 46Bwhich is divergent then forces the material to split apart a second timeand flow to each respective second wall 48A and 48B. As with the firstwall 40A and 40B, the material, upon reaching the second wall 48A and48B can no longer flow in an x-y plane and must instead move in atransverse z-direction. For example, at the Wall 48A, the material flowsfrom a point ″2 in one half 22A to a corresponding point ″2 in the otherhalf 22B, which lies in a second convergent portion 50B. The materialreaching the wall 48B flows from a point $2 in one half 22B to acorresponding point $2 in the other half 22A, which lies in a secondconvergent portion 50A.

[0065] In the shown embodiment, each second convergent portion 50A and50B, is parallel to each second diverging branching intersection 46A and46B. For example, the portion 50A is parallel to the portion 46A and theportion 50B is parallel to the portion 46B. The second convergentportion 50A and 50B forces the material into a second common area 52Aand 52B to once again rejoin the separated material. As with the firstcommon area 44A and 44B, the second common area 52A and 52B has a fullcircular cross section.

[0066] After the common area 52A and 52B, a third branching intersection54A and 54B again diverges, separating the material and conveying it indifferent directions. Upon reaching each respective third wall, i.e.,the wall 56A in the portion 54A and the wall 56B in the portion 54B, thematerial is forced to again flow in a transverse, z-direction from theplanar x-y direction. From a point 3 at the third wall 56A in one half22A, the material flows to a corresponding point 3 in the other half22B, which lies in a third convergent portion 58B. Correspondingly, froma point 3 at third wall 56B in one half 22B, the material flows to acorresponding point 3 in the other half 22A, which is in a thirdconvergent portion 58A.

[0067] The turbulence-promoting after-mixer structure 30A and 30B endswith a third convergent portion 58A and 58B returning the separatedmaterial to the connecting flow channel 32A and 32B. The connectingchannel 32A and 32B is a common, uniform circular channel having acurvature of 360 degrees. Once the material enters the connectingchannel portion 32A and 32B, typical straight or curved smooth linearflow recommences.

[0068] By separating and recombining materials repeatedly as they flow,the present invention provides for increased mixing of constituentmaterials. Through the incorporation of split channels and transverseflow, mixing is encouraged and controlled while the flow remainsuniform, reducing back flow or hanging-up of material, thereby reducingthe degradation often involved in non-linear flow. Particular note ismade of the angles of divergence and convergence of the after-mixerportions 38A and 38B, 42A and 42B, 46A and 46B, 50A and 50B, 54A and 54Band 58A and 58B, as each extends at the angle of about 30 degrees to 60degrees from the centerline of the linear inlet flow channel 28A, 28B.This range of angles allows for rapid separation and re-convergencewhile minimizing back flow. In addition, each divergent branchingportion and converging portion 38A and 38B, 42A and 42B, 46A and 46B,50A and 50B, 54A and 54B and 58A and 58B extends from the centerline ofthe linear inlet flow channel 28A, 28B for a distance of one to threetimes the diameter of the channel 28A, 28B before reaching itsrespective wall 40A and 40B, 48A and 48B and 56A and 56B. Further noteis made of the common areas 44A and 44B and 52A and 52B. These areas aredirectly centered about a same linear centerline which extends from theinlet flow channel portion 28A, 28B to the commencement of theconnecting flow channel portion 32A, 32B. As a result, the common areas44A and 44B and 52A and 52B are aligned linearly with the channelportions 28A, 28B and 32A, 32B, providing for more consistent, uniformflow. While several divergent, convergent, and common portions areillustrated, it is anticipated that as few as one divergent andconvergent portion or as many as ten to twenty divergent and convergentportions may be used, depending upon the application and materialsinvolved.

[0069]FIG. 6 depicts the turbulence-promoting after-mixer channels 30A,30B from a side view when the molding assembly 20 is closed. Asdescribed above, upon closure, the upper half 22A and the lower half 22Bmeet, thereby creating the turbulence-promoting after-mixer along theregion of the channel portions 30A and 30B. The resulting flow pathwaycauses the constituent materials flowing therethrough to deviate from astraight, generally linear path to a nonlinear turbulence-promotingpath. The interaction and alignment of the divergent branchingintersections 38A and 38B, 46A and 46B, 54A and 54B (referencing back toFIG. 5), the convergent portions 42A and 42B, 50A and 50B, 58A and 58B,and the common portions 44A and 44B, and 52A and 52B, also as describedabove, is shown in detail.

[0070] In a particularly preferred embodiment, the after-mixer includesa plurality of bends or arcuate portions that cause liquid flowingthrough the fan gate to not only be directed in the same plane in whichthe flow channel lies, but also in a second plane that is perpendicularto the first plane. It is most preferable to utilize an after-mixer withbends such that liquid flowing therethrough travels in a plane that isperpendicular to both the previously noted first and second planes. Thisconfiguration results in relatively thorough and efficient mixing due tothe rapid and changing course of direction of liquid flowingtherethrough.

[0071] The configuration of the mold channels may take various forms.One such variation is shown in FIG. 7. Reference is made to the lowermold half 22B for the purpose of illustration, and it is to beunderstood that the upper mold half 22A (not shown) comprises acomplimentary configuration. The adapter portion 26B leads to the inletflow channel 28B which leads to the turbulence-promoting channel portion30B. However, instead of the adapter 26B and the channels 28B and 30Bbeing spaced apart from the central cavity 24B, they are positionedapproximately in line with the central cavity 24B, eliminating the needfor the connecting channel portion 32B to be of a long, curvedconfiguration to reach the fan gate portion 34B. Thus, the connectingchannel 32B is a short, straight channel, promoting a material flow pathwhich may be more desirable for some applications. The flow channels andthe central cavity may be arranged according to other forms similar tothose shown, which may occur to one skilled in the art, as equipmentconfigurations and particular materials and applications dictate. FIG. 7also illustrates one or more nonretractable protrusions 36 in themolding chamber.

[0072] In the above-referenced figures, the channels 30A and 30B aredepicted as each comprising a plurality of angled bends or turns.Turning now to FIG. 8, the channels are not limited to the angledbend-type fan gate configuration and include any turbulence-promotingdesign located in a region 59B between the adapter portion 26B and thecavity 24B. Again, reference is made to the lower mold half 22B for thepurpose of illustration, and it is to be understood that the upper moldhalf 22A (not shown) is complimentary to the lower mold half 22B. Thechannels in the turbulence-promoting region 59A (not shown) and 59Bcould be formed to provide one or more arcuate regions such that uponclosure of the upper and lower mold halves 22A and 22B, the flow gatehas, for example, a spiral or helix configuration. Regardless of thespecific configuration of the channels in the turbulence promotingportion 59A and 59B, the shape of the resulting flow gate insures thatthe materials flow through the turbulence-promoting region andthoroughly mix with each other, thereby reducing typical straightlaminar flow and minimizing any settling in a low-flow area wheredegradation of flow may occur. Preferably, the shape and configurationof the flow channel is such that the velocity of the materials flowingtherethrough is generally constant at different locations along thechannel. And, as previously noted, such flow characteristics andthorough mixing of the materials has been found to lead to greaterconsistency and uniformity in the final physical properties andcharacteristics of the resulting golf ball layer or component. FIG. 8further illustrates one or more protrusions 36 in the molding chamber.

[0073] As shown in FIG. 9, the turbulence-promoting region 59A (notshown) and 59B may be placed in various locations in the upper and lowermold halves 22A (not shown) and 22B. As mentioned above, theturbulence-promoting region 59B and the other flow channel portions 28B,32B, and 34B may be arranged so as to create an approximately straightlayout between the adapter portion 26B and the central cavity 24B. Byallowing flexibility in the location of the turbulence-promoting region59B and the other channel portions 28B, 32B and 34B, as well as theadapter 26B and the central cavity 24B, optimum use may be made of thepresent invention in different applications. FIG. 9 also illustrates oneor more protrusions 36 in the molding chamber.

[0074] Gases, including air and moisture, are often present in a RIMprocess and create undesirable voids in the molded cover 14. Venting ofcentral cavity 24A, 24B reduces voids by removing these gases. Throughthe use of venting, a cover 14 is provided that is significantly morefree from voids or other imperfections than a cover produced by anon-vented RIM process.

[0075] A preferred method of making a golf ball in accordance with thepresent invention is illustrated in FIG. 10. A golf ball core 12 made bytechniques known in the art is obtained, illustrated as step 70. Thecore 12 is preferably positioned within a mold having ventingprovisions, after-mixers, and fan gates as described herein. This isillustrated as step 72. It is preferred that the core 12 is supported ona plurality of the previously described protrusions 36 that form deepdimples in the final ball. This is shown as step 74. The mold is thenclosed. This is illustrated as step 75. The cover layer 14 is moldedover the core 12 by RIM as step 76. If venting of gases from the moldingcavity is desired, such gases are preferably vented as previouslydescribed. This is designated as step 78. Should increased removal ofgases be desired, the venting of step 78 is enhanced by providing avacuum connection as known in the art to the venting channel. When themolding is complete, the golf ball 10 is removed from the mold, as shownby steps 79 and 80.

[0076] In accordance with conventional molding techniques, the preferredembodiment molding processes described herein may utilize one or moremold release agents to facilitate removal of the molded layer orcomponent from the mold.

[0077] A golf ball manufactured according the preferred method describedherein exhibits unique characteristics. Golf ball covers made throughcompression molding and traditional injection molding include balata,ionomer resins, polyesters resins and polyurethanes. The selection ofpolyurethanes which can be processed by these methods is limited.Polyurethanes are often a desirable material for golf ball coversbecause balls made with these covers are potentially more resistant toscuffing and resistant to deformation than balls made with covers ofother materials. The current invention allows processing of a wide arrayof grades of polyurethane through RIM which was not previously possibleor commercially practical utilizing either compression molding ortraditional injection molding. It is anticipated that other urethaneresins such as Bayer® MP-7500, Bayer® MP-5000, Bayer® aliphatic or lightstable resins, and Uniroyal® aliphatic and aromatic resins may be used.For example, utilizing the present invention method and Bayer® MP-10000polyurethane resin, a golf ball with the properties described below hasbeen provided. Also, depending upon the application, BASF aromatic oraliphatic resins may be used.

[0078] Some of the unique characteristics exhibited by a golf ballaccording to the present invention include a thinner cover without theaccompanying disadvantages otherwise associated with relatively thincovers such as weakened regions at which inconsistent compositionaldifferences exist. A traditional golf ball cover typically has a totalthickness in the range of about 0.060 inches to 0.080 inches. A golfball of the present invention may utilize a cover having a thickness offrom about 0.002 inches to about 0.100 inches, more preferably fromabout 0.005 inches to about 0.075 inches, more preferably from about0.010 inches to about 0.050 inches, and most preferably from about 0.015inches to about 0.050 inches. This reduced cover thickness is often adesirable characteristic. It is contemplated that thinner layerthicknesses are possible using the present invention.

[0079] Because of the reduced pressure involved in RIM as compared totraditional injection molding, an outer cover or any other layer of thepresent invention golf ball is more dependably concentric and uniformwith the core of the ball, thereby improving ball performance. That is,a more uniform and reproducible geometry is attainable by employing thepresent invention.

[0080] The present invention also provides a golf ball in which at leastone cover or core layer is a fast-chemical-reaction-produced component.This component comprises at least one material selected from the groupconsisting of polyurethane, polyurea, polyurethane ionomer, epoxy, andunsaturated polyesters, and preferably comprises polyurethane. Theinvention also includes a method of producing a golf ball which containsa fast-chemical-reaction-produced component. A golf ball formedaccording to the invention preferably has a flex modulus in the range offrom about 5 to about 310 kpsi, a Shore D hardness in the range of fromabout 20 to about 90, and good durability. Particularly preferred formsof the invention also provide for a golf ball with afast-chemical-reaction-produced cover having good scuff resistance andcut resistance. As used herein, “polyurethane and/or polyurea” isexpressed as “polyurethane/polyurea”.

[0081] A particularly preferred form of the invention is a golf ballwith a cover comprising polyurethane, the cover including from about 5to about 100 weight percent of polyurethane formed from recycledpolyurethane.

[0082] The method of the invention is particularly useful in forminggolf balls because it can be practiced at relatively low temperaturesand pressures. The preferred temperature range for the method of theinvention is from about 50° F. to about 250° F. and preferably fromabout 120° F. to about 180° F. when the component being producedcontains polyurethane. Preferred pressures for practicing the inventionusing polyurethane-containing materials are 200 psi or less and morepreferably 100 psi or less. The method of the present invention offersnumerous advantages over conventional slow-reactive process compressionmolding of golf ball covers. The method of the present invention resultsin molded covers in a demold time of 10 minutes or less. An excellentfinish can be produced on the ball.

[0083] The method of the invention also is particularly effective whenrecycled polyurethane or other polymer resin, or materials derived byrecycling polyurethane or other polymer resin, is incorporated into theproduct.

[0084] As indicated above, the fast-chemical-reaction-produced componentcan be one or more cover and/or core layers of the ball. When apolyurethane cover is formed according to the invention, and is thencovered with a polyurethane top coat, excellent adhesion can beobtained. The adhesion in this case is better than adhesion of apolyurethane coating to an ionomeric cover. This improved adhesion canresult in the use of a thinner top coat, the elimination of a primercoat, and the use of a greater variety of golf ball printing inksbeneath the top coat. These include but are not limited to typical inkssuch as one component polyurethane inks and two component polyurethaneinks.

[0085] More specifically, the preferred method of forming afast-chemical-reaction-produced component for a golf ball according tothe invention is by RIM. In this approach, highly reactive liquids areinjected into a closed mold, mixed usually by impingement and/ormechanical mixing and secondarily mixed in an in-line device such as apeanut mixer, where they polymerize primarily in the mold to form acoherent, one-piece molded article. The RIM processes usually involve arapid reaction between one or more reactive components such aspolyether—or polyester—polyol, polyamine, or other material with anactive hydrogen, and one or more isocyanate—containing constituents,often in the presence of a catalyst. The constituents are stored inseparate tanks prior to molding and may be first mixed in a mix headupstream of a mold and then injected into the mold. The liquid streamsare metered in the desired weight to weight ratio and fed into animpingement mix head, with mixing occurring under high pressure, e.g.,1500 to 3000 psi. The liquid streams impinge upon each other in themixing chamber of the mix head and the mixture is injected into themold. One of the liquid streams typically contains a catalyst for thereaction. The constituents react rapidly after mixing to gel and formpolyurethane polymers. Polyureas, epoxies, and various unsaturatedpolyesters also can be molded by RIM.

[0086] As previously noted, RIM differs from non-reaction injectionmolding in a number of ways. The main distinction is that in RIM achemical reaction takes place in the mold to transform a monomer oradducts to polymers and the components are in liquid form. Thus, a RIMmold need not be made to withstand the pressures which occur in aconventional injection molding. In contrast, injection molding isconducted at high molding pressures in the mold cavity by melting asolid resin and conveying it into a mold, with the molten resin oftenbeing at about 150 to about 350° C. At this elevated temperature, theviscosity of the molten resin usually is in the range of 50,000 to about1,000,000 centipoise, and is typically around 200,000 centipoise. In aninjection molding process, the solidification of the resins occurs afterabout 10 to 90 seconds, depending upon the size of the molded product,the temperature and heat transfer conditions, and the hardness of theinjection molded material. Subsequently, the molded product is removedfrom the mold. There is no significant chemical reaction taking place inan injection molding process when the thermoplastic resin is introducedinto the mold. In contrast, in a RIM process, the chemical reactiontypically takes place in less than about 2 minutes, preferably in underone minute, and in many cases in about 30 seconds or less.

[0087] If plastic products are produced by combining components that arepreformed to some extent, subsequent failure can occur at a location onthe cover which is along the seam or parting line of the mold. Failurecan occur at this location because this interfacial region isintrinsically different from the remainder of the cover layer and can beweaker or more stressed. The present invention is believed to providefor improved durability of a golf ball cover layer by providing auniform or seamless cover in which the properties of the cover materialin the region along the parting line are generally the same as theproperties of the cover material at other locations on the cover,including at the poles. The improvement in durability is believed to bea result of the fact that the reaction mixture is distributed uniformlyinto a closed mold. This uniform distribution of the injected materialsreduces or eliminates knit-lines and other molding deficiencies whichcan be caused by temperature difference and/or reaction difference inthe injected materials. The process of the invention results ingenerally uniform molecular structure, density and stress distributionas compared to conventional injection-molding processes.

[0088] The fast-chemical-reaction-produced component has a flex modulusof from about 1 to about 310 kpsi, more preferably from about 1 to about100 kpsi, and most preferably from about 2 to about 50 kpsi. The subjectcomponent can be a cover with a flex modulus which is higher than thatof the centermost component of the cores, as in a liquid center core andsome solid center cores. Furthermore, thefast-chemical-reaction-produced component can be a cover with a flexmodulus that is higher than that of the immediately underlying layer, asin the case of a wound core. The core can be one piece or multi-layer,each layer can be either foamed or unfoamed, and density adjustingfillers, including metals, can be used. The cover of the ball can beharder or softer than any particular core layer.

[0089] The fast-chemical-reaction-produced component can incorporatesuitable additives and/or fillers. When the component is an outer coverlayer, pigments or dyes, accelerators and UV stabilizers can be added.Examples of suitable optical brighteners which probably can be usedinclude Uvitex? and Eastobrite? OB-1. An example of a suitable whitepigment is titanium dioxide. Examples of suitable and UV lightstabilizers are provided in commonly assigned U.S. Pat. No. 5,494,291.Fillers which can be incorporated into thefast-chemical-reaction-produced cover or core component include thoselisted below in the definitions section. Furthermore, compatiblepolymeric materials can be added. For example, when the componentcomprises polyurethane and/or polyurea, such polymeric materials includepolyurethane ionomers, polyamides, etc.

[0090] A golf ball core layer formed from afast-chemical-reaction-produced material according to the presentinvention typically contains 0 to 20 weight percent of such fillermaterial, and more preferably 1 to 15 weight percent. When thefast-chemical-reaction-produced component is a core, the additivestypically are selected to control the density, hardness and/or COR.

[0091] A golf ball inner cover layer formed from afast-chemical-reaction-produced material according to the presentinvention typically contains 0 to 60 weight percent of filler material,more preferably 1 to 30 weight percent, and most preferably 1 to 20weight percent.

[0092] A golf ball outer cover layer formed from afast-chemical-reaction-produced material according to the presentinvention typically contains 0 to 20 weight percent of filler material,more preferably 1 to 10 weight percent, and most preferably 1 to 5weight percent.

[0093] Catalysts can be added to the RIM polyurethane system startingmaterials as long as the catalysts generally do not react with theconstituent with which they are combined. Suitable catalysts includethose which are known to be useful with polyurethanes and polyureas.

[0094] The reaction mixture viscosity should be sufficiently low toensure that the empty space in the mold is completely filled. Thereactant materials generally are preheated to about 80° F. to about 200°F. and preferably to 100° F. to about 180° F. before they are mixed. Inmost cases it is necessary to preheat the mold to, e.g., from about 80°F. to about 200° F., to provide for proper injection viscosity.

[0095] As indicated above, one or more cover layers of a golf ball canbe formed from a fast-chemical-reaction-produced material according tothe present invention.

[0096] Referring to FIG. 11, another preferred embodiment golf ballhaving a cover comprising a RIM polyurethane is shown. The golf ball 110includes a polybutadiene core 112 and a polyurethane cover 114 formed byRIM. The golf ball 110 defines a plurality of dimples 116 along itsouter surface. Preferably, the ball 110 also defines one or more deepdimples 118 as described in greater detail herein.

[0097] Referring now to FIG. 12, the golf ball 110 having a corecomprising a RIM polyurethane is shown. The golf ball 110 has a RIMpolyurethane core 112, and a RIM polyurethane cover 114. The golf ball110 defines a plurality of dimples 116 along its outer surface.Preferably, the ball 110 also defines one or more deep dimples 118 asdescribed in greater detail herein.

[0098] Referring to FIGS. 13 and 14, a multi-layer golf ball 210 isshown with a solid core 212 containing recycled RIM polyurethane, amantle cover layer comprising RIM polyurethane 213, and an outer coverlayer 214 comprising ionomer or another conventional golf ball covermaterial. Non-limiting examples of multi-layer golf balls according tothe invention with two cover layers include those with RIM polyurethanemantles having a thickness of 0.01 to 0.20 inches, or thinner, and aShore D hardness of 20 to 80, covered with ionomeric or non-ionomericthermoplastic, balata or other covers having a Shore D hardness of 20 to80 and a thickness of 0.010 to 0.20 inches. The golf ball 210 defines aplurality of dimples 216 along its outer surface. Preferably, the ball210 also defines one or more deep dimples 218 as described in greaterdetail herein.

[0099] Referring again to FIGS. 11 and 12, those figures illustrate apreferred embodiment golf ball 110 produced in accordance with thepresent invention. One or more of the deep dimples 120, and preferablytwo or more of the dimples 120, and more preferably three or more of thedimples per hemisphere, extend into the core 112 disposed underneath thecover layer 114. These dimples are herein referred to as deep dimples.

[0100] The preferred embodiment golf ball 210 shown in FIGS. 13 and 14comprises a core 212 having an inner cover layer 213 disposed thereonand an outer cover layer 214 formed about the inner cover layer 213. Thecover layers 213 and 214 define a plurality of dimples 216 along theouter surface of the outer cover layer 160. One or more of the dimples,and preferably two or more of the dimples, and more preferably three ormore of the dimples per hemisphere, extend entirely through the outercover layer 214 and at least partially into or to the inner cover layer213. These dimples, which extend through the outer cover layer, areagain referred to herein as deep dimples and shown in FIG. 13 as dimples218.

[0101] The deep dimples can be circular, non-circular, a combination ofcircular and non-circular, or any other shape desired. They may be ofthe same or differing shape, such as a circular larger dimple having anoval smaller dimple within the circular dimple, or an oval larger dimplehaving a circular or other shape within the larger dimple. The dimplesdo not have to be symmetrical.

[0102] Providing deep dimples formed in multiple layers allows thedimple depth to be spread over two or more layers. FIG. 13 illustratesdeep dimple 220 formed in both the inner cover layer and the outer coverlayer. The inner portion of the dimple 220 is formed in the inner coverlayer 213, and the outer portion of the dimple 220 is formed in theouter cover layer 214. For a two-piece ball, dimples may be formed inthe core and the single cover layer in the same way as previouslydescribed. Additionally, dimples may be formed in more than two coverand/or core layers if desired.

[0103] In another preferred embodiment, a multi-layer golf ball isproduced that has one or more deep dimples that protrude into the ballthrough at least one layer, such as an outer cover layer. In a furtherpreferred embodiment, the deep dimple protrudes through at least twolayers. The dimples of the at least two layers are configured with thesame geometric coordinates (that is, the approximate center of the bothdimples would be in the same location, and so the dimples are concentricwith respect to each other), producing a golf ball having a dimpledlayer over a dimpled layer. This allows for much thinner layers withtraditional dimples. The dimples of one or more inner layers may be ofvarying depths, diameters and radii, yet still aligned with the dimplesof the outer layer. This also allows for a dimple within a dimple, wherethere is a smaller dimple in at least one inner or mantle layer that iswithin a larger diameter dimple in the outer layer, such as the dimplesshown in FIGS. 15 to 18.

[0104] FIGS. 15 to 18 illustrate a deep dimple that is a dual radiusdimple, or a dimple within a dimple. One advantage of a dual radiusdimple is that the deeper part of the dual radius may be filled in witha coating or other material. This provides an effective method forforming dimple depths to a desired value as compared to other methods ofdimple formation. The dimple shape may be any shape desired, and eachdimple may be the same or different shape. Preferably, the depth of thesecond or deepest portion of the dual radius dimple may be expressed asa percentage of the total depth of the dimple. Specifically, the regionor portion of the dimple which extends to the outermost surface of theball may be referred to herein as the “major” dimple. And, likewise, theportion of the dimple which extends to the deepest portion or depth ofthe dimple can be referred to herein as the “minor” dimple. Accordingly,the preferred depth of the major dimple is approximately from about 40%to about 80% of the overall dimple depth. Accordingly, the preferreddepth of the minor dimple is approximately 20% to about 60% of theoverall dimple depth. The depth being measured from the chord of themajor dimple to the bottom of the minor dimple. With regard todiameters, the preferred diameter of the minor dimple is from about 10%to about 70% of the diameter of the major dimple.

[0105]FIG. 15 is a cross-sectional detail illustrating a portion of apreferred embodiment golf ball produced in accordance with the presentinvention. This preferred embodiment golf ball 310 comprises a core 320having a cover layer 330 formed thereon. The cover layer defines atleast one deep dimple 340 along its outer surface 335. As previouslydescribed, it is preferred that one or more (preferably two or more,more preferably three or more per hemisphere) of the dimples extendsentirely through the cover layer and into the core disposed underneaththe cover layer. FIG. 15 illustrates a deep dimple defined by twodifferent curvatures. Referring to FIG. 15, a first radius R₁ definesthe portion of the dimple from the outer surface 335 of the golf ball310 to a point at which the deep dimple extends into a layer underneaththe cover layer. At this point, the curvature of the dimple changes andis defined by radius R₂. Preferably, R₁, is from about 0.130 inches toabout 0.190 inches, and most preferably, R₁, is from about 0.140 toabout 0.180 inches. For some embodiments, R₁ ranges from about 0.100inches to about 1.000 inch, and most preferably from about 0.200 inchesto about 0.800 inches. Preferably, R₂ is from about 0.025 inches toabout 0.075 inches, and most preferably, R₂ is about 0.050 to about0.065 inches. For some embodiments, R₂ ranges from about 0.002 inches toabout 0.500 inches, and most preferably from about 0.010 inches to about0.200 inches. The overall diameter or span of the dimple 340 isdesignated herein as D₁. The diameter or span of the portion of thedimple that extends into the layer underneath the outer cover layer isdesignated herein as D₂. Preferably, D₁ is from about 0.030 inches toabout 0.250 inches, more preferably from about 0.100 inches to about0.186 inches, and most preferably, D₁ is about 0.146 inches to about0.168 inches. For some embodiments, D₁ ranges from about 0.100 inches toabout 0.250 inches, and most preferably D₁ is about 0.140 inches toabout 0.180 inches. Preferably D₂ is from about 0.020 inches to about0.160 inches, more preferably from about 0.030 inches to about 0.080inches, and most preferably, D₂ is about 0.056 inches. For someembodiments, D₂ is from about 0.040 inches to about 0.060 inches.Accordingly, the overall depth of the deep dimple portion that isdefined by R₁ is designated herein as H₁ and the depth or portion of thedimple that is defined by R₂ is designated herein as H₂. Preferably, H₁is from about 0.005 inches to about 0.135 inches, more preferably fromabout 0.005 to about 0.025 inches, more preferably from about 0.010inches to about 0.015 inches, and most preferably, H₁ is about 0.015inches. For some embodiments, H₁ is from about 0.005 inches to about0.015 inches. H₂ may range from about 0.005 inches to about 0.135inches, and more preferably from about 0.005 to about 0.050 inches.Preferably, H₂ ranges from about 0.005 inches to about 0.030 inches andis about 0.010 inches. For some embodiments, H₂ is from about 0.005inches to about 0.015 inches.

[0106] Referring to FIG. 16, another preferred embodiment golf ball 410is illustrated. In this version of the present invention, a golf ball410 comprises a core 420 and a cover layer 430 formed thereon. The coverlayer 430 defines at one deep dimple 440 along the outer surface 435 ofthe golf ball 410. As can be seen, the dimple 440 is defined by twodifferent curvatures, each of which is defined by radii R₂ and R₁ aspreviously described with respect to FIG. 15. The other parameters D₁,D₂, H₁, and H₂ are as described with respect to FIG. 15. FIG. 16illustrates an embodiment in which the dimple 440 extends to the core420 and not significantly into the core. In contrast, the versionillustrated in FIG. 15 is directed to a dimple configuration in which adimple extends significantly into the underlying core.

[0107]FIG. 17 illustrates a preferred embodiment golf ball 510comprising a core 520, a mantle or inner cover layer 550, and an outercover layer 560. The outer cover layer 560 and inner cover layer 550define at least one deep dimple 540 along the outer surface 535 of theball 510. The dimple 540 is defined by two different regions or twocurvatures, each of which is in turn defined by radii R₂ and R₁. Theother parameters D₁, D₂, H₁, and H₂ are as described with respect toFIG. 15. As can be seen in FIG. 17, the dimple 540 extends entirelythrough the outer cover layer 560 and into the inner cover layer ormantle layer 550.

[0108]FIG. 18 illustrates another preferred embodiment golf ball 610 inaccordance with the present invention. The golf ball 610 comprises acore 620 having disposed thereon an inner cover layer or mantle layer650 and an outer cover layer 660. Defined along the perimeter or outerperiphery of the ball 610 is at least one deep dimple 640. The dimple640 is defined along the outer surface 635 of the ball 610. The dimple640 has two different regions or curvatures each defined by radii R₂ andR₁. The other parameters D₁, D₂, H₁, and H₂ are as described withrespect to FIG. 15. The version illustrated in FIG. 18 reveals a dimple640 that does not significantly extend into the mantle layer or innercover layer 650. Instead, the dimple 640 only extends to the outermostregion of the mantle layer or inner cover layer 650.

[0109] An important characteristic of dimple configuration is the volumeratio. The volume ratio is the sum of the volume of all dimples takenbelow a chord extending across the top of a dimple, divided by the totalvolume of the ball. The volume ratio is a critical parameter for ballflight. A high volume ratio generally results in a low flying ball. Anda low volume ratio often results in a high-flying ball. A preferredvolume ratio is about 1%. The balls of the present invention however maybe configured with greater or lesser volume ratios.

[0110] The number and/or layout of dimples will not necessarily changethe coverage, i.e. surface area. A typical coverage for a ball of thepresent invention is about 60% to about 90% and preferably about 83.8%.In other embodiments, this preferred coverage is about 84% to about 85%.These percentages are the percent of surface area of the ball occupiedby dimples. It will be appreciated that the present invention golf ballsmay exhibit coverages greater or less than that amount.

[0111] For configurations utilizing dimples having two or more regionsof different curvature, i.e. dimple within a dimple, there is lessimpact on the volume ratio than the use of deep dimples. If there areenough of either dimples within dimples or deep dimples, theaerodynamics of the ball will eventually be impacted.

[0112] The optimum or preferred number of deep dimples utilized per ballvaries. It is the amount necessary to secure or center the core or coreand cover layer(s) during molding without adversely affecting theaerodynamics of the finished ball. However, the present inventionincludes the use of a relatively large number of deep dimples. That is,although most of the focus of the present invention is directed to theuse of only a few deep dimples per golf ball, i.e. from 2 to 6, theinvention includes the use of a significantly greater number such asfrom about 50 to about 250. It is also contemplated that for someapplications, it may be desirable to form all, or nearly all, dimples ona golf ball as deep dimples such as, for example, from about 50 to about500.

[0113] In certain golf ball embodiments, it may be desirable to form aparticular proportion of the dimples along the outer surface of the golfball as deep dimples. The proportion selected may depend uponaesthetics, aerodynamic effects, marketability factors, ballperformance, manufacturing, or other factors. Generally, the proportionof dimples that may be formed as deep dimples may be all, substantiallyall, a majority, half, a minority, or a minor number.

[0114] More specifically, in certain embodiments, it is desirable toform a specific proportion of all dimples along the outer surface of agolf ball as deep dimples. For instance, it may be desirable to form alldimples, i.e. 100%, as deep dimples. In other embodiments, it may bedesirable to form at least 95% of all dimples as deep dimples. Or, itmay be desirable to form at least 90% of all dimples as deep dimples.Alternatively, it may be desirable to form at least 85% , at least 80%,at least 75%, at least 70%, at least 65%, at least 60% , at least 55%,at least 50%, at least 45%, at least 40%, at least 35%, at least 30%, atleast 25%, at least 20%, at least 15%, at least 10%, at least 5%, or atleast 1% as deep dimples.

[0115] In forming golf balls with a particular number of deep dimples,it will be appreciated that the molding equipment employed to form suchballs utilizes a molding chamber having a molding surface with acorresponding number of outwardly extending protuberances or projectionsas described herein.

[0116] Furthermore, the processes and equipment described herein forreaction injecting molding a polyurethane or polyurethane derivativematerial, are well suited for forming a golf ball with a relativelylarge proportion of deep dimples. Although not wishing to be bound toany particular theory or limiting reason, it is believed that the mixingand molding characteristics of the molding material and that associatedwith the process and equipment, enable and promote the formation of oneor more cover layers that define a large number of well defined deepdimples.

[0117] One particularly preferred embodiment golf ball includes multiplepopulations of dimples along its outer surface. For example, two, three,four, five, six or more different types or populations of dimples may beprovided. One or more of the multiple populations are preferably deepdimples. The other populations may include a wide array of dimple typessuch as, but not limited to, conventional dimples, non-conventionaldimples, or dimples known in the prior art.

[0118] In general, as dimples are made deeper, the ball will fly loweras compared to the use of dimples that are shallower. As the number ofdeep dimples increases, the ball will exhibit a lower flight trajectory.Accordingly, the preferred approach is to utilize a smaller number ofdeep dimples. However, for other applications, the present inventionincludes a ball with many deep dimples.

[0119] The overall shape of the dimples, including deep dimples, may benearly any shape. For example, shapes such as hexagon, pentagon,triangle, ellipse, circle, etc. are all suitable. There is no limit tothe number of shapes, although some shapes are preferred over others. Atpresent, circular dimples are preferred. As for the cross-sectionalconfiguration, the dimples may utilize any geometry. For instance,dimples may be defined by a constant curve or a multiple curvature ordual radius configuration or an elliptical or teardrop shaped region.

[0120]FIG. 19 illustrates a preferred embodiment molding apparatus 1000in accordance with the present invention. Molding apparatus 1000comprises two mold halves 1020 and 1040 that each define a hemisphericalportion of a molding chamber 1024 and 1044. Defined along the outersurface of the hemispherical portion of the molding chamber 1024 are aplurality of raised protrusions or support pins 1032. These raisedregions or support pins form dimples in a cover layer in a golf ballformed using molding apparatus 1000. Also provided along the outersurface of the hemispherical molding chamber 1024 are a plurality ofoutwardly extending or raised regions or support pins 1026, 1028, and1030. These raised regions are of a height greater than the height ofthe raised regions 1032. Specifically, the raised regions 1026, 1028,and 1030 form deep dimples as described herein. These raised regions areused to retain and support a golf ball core placed in the mold. Theseraised regions also serve to form deep dimples 1018 in the golf ball1010. A passage 1022 is provided in the mold half 1020 as will beappreciated. The passage 1022 provides communication and a path for aflowable moldable material to be introduced into the molding chamber.The molding apparatus 1000 also includes a second molding portion orplate 1040. The plate 1040 defines a hemispherical molding chamber 1044also having a plurality of raised regions or support pins along itsouter surface. Specifically, raised regions 1046 and 1048 are providedsimilar to the previously described raised regions 1026, 1028, and 1030.The molding plate 1040 also defines a channel 1042 extending from themolding chamber 1044 to the exterior of the plate. Most preferably, themolding channel 1042 is aligned with channel 1022 in the other plate1020 when the mold is closed to provide a unitary passage providingcommunication between the molding chamber and the exterior of the mold.It will be appreciated that this figure is not necessarily to scale, andso channel 1042 would likely be significantly smaller in a commercialmanufacturing application. Preferably, a turbulence-inducing after-mixeris provided in the mold halves as previously described in conjunctionwith FIGS. 2-9. Similarly, provisions for a dump well and associatedventing are also provided as previously described. A golf ball coreplaced in the molding chamber 1024,1044 is supported by the variousraised regions 1026, 1028, 1030, 1046, and 1048 as previously described.Upon molding a suitable cover layer on the core or intermediate ballassembly, the golf ball 1010 is produced.

[0121] Certain preferred embodiment molding equipment in accordance withthe present invention utilize molds with molding surfaces that provide acollection of different types or heights of raised regions or outwardlyextending projections. Specifically, it may in some instances bedesirable to provide a molding surface with a first population of raisedregions that define a first type of dimple and another population ofraised regions that define deep dimples as described herein. The secondor other population of raised regions that form deep dimples mayconstitute a minority proportion or a majority proportion of all thedimples defined on the resulting golf ball. It is also contemplated toprovide a number of different shapes, sizes, heights, and configurationsor raised regions along a molding surface. As will be appreciated, thisis an efficient manner to form a golf ball with a relatively largenumber of deep dimples.

[0122] Additionally, golf balls of the present invention that comprisepolyurethane/polyurea (or other suitable materials) in any of the innerand outer cover layer may be produced by RIM, as previously described.

[0123] Golf balls and, more specifically, cover layers formed by RIM arepreferably formed by the process described in application Ser. No.09/040,798, filed Mar. 18, 1998, incorporated herein by reference, or bya similar RIM process.

[0124] The golf balls, and particularly the cover layer(s), of thepresent invention may also be formed by liquid injection molding (LIM)techniques, or any other method known in the art.

[0125] The golf balls formed according to the present invention can becoated using a conventional two-component spray coating or can be coatedduring the RIM process, for example, using an in-mold coating process.

[0126] Referring next to FIG. 20, a process flow diagram for forming aRIM cover of polyurethane is shown. Isocyanate from bulk storage is fedthrough line 1180 to an isocyanate (or polyisocyanate) tank 1200. Theisocyanate is heated to the desired temperature, e.g., 80° F. to about220° F., by circulating it through heat exchanger 1182 via lines 1184and 1186. Polyol, polyamine, or another compound with an active hydrogenatom is conveyed from bulk storage to a polyol tank 1208 via line 1188.The polyol is heated to the desired temperature, e.g., 90° F. to about180° F., by circulating it through heat exchanger 1190 via lines 1192and 1194. Generally, it is preferred to heat each reactive componentsuch as the isocyanate and the polyol, to a temperature such that theyhave the same viscosity. Preferably, these temperatures are about 80° F.to about 220° F. for the polyol component and about 80° .F to about 220°F. for the isocyanate component. More preferably, the polyol is at atemperature of about 100° F. and the isocyanate is at about 200° F. Drynitrogen gas is fed from nitrogen tank 1196 to isocyanate tank 1200 vialine 1197 and to polyol tank 1208 via line 1198. This gaseous blanket isused to prevent oxidation or other deleterious reaction of the injectioncomponents. Isocyanate is fed from isocyanate tank 1200 via line 1202through a metering cylinder or metering pump 1204 into recirculation mixhead inlet line 1206. An isocyanate recirculation line 1250 ispreferably utilized. Polyol is fed from polyol tank 1208 via line 1210through a metering cylinder or metering pump 1212 into a recirculationmix head inlet line 1214. A polyol recirculation line 1260 is preferablyutilized. A recirculation mix head 1216 receives isocyanate and polyol,mixes them, and provides for them to be fed through nozzle 1218 intoinjection mold 1220. The injection mold 1220 has a top mold 1222 and abottom mold 1224. Heat exchange fluid flows through cooling lines 1226in the top mold 1222 and lines 1240 in the bottom mold 1224. Thematerials are kept under controlled temperature conditions so that thedesired reaction profile is maintained. Preferably, controlledtemperatures are maintained by using oil heaters or other heating mediumalong the entirety of each of the paths or lines for the reactants.Preferably, temperature control of the isocyanate lines 1202 and 1250 isachieved by use of a heat exchanger 1300 and heat exchange line 1302 asshown in FIG. 22. Similarly, temperature control of the polyol lines1210 and 1260 is achieved by use of a heat exchanger 1310 and heatexchange line 1312 as shown in FIG. 23. Most preferably, a multiple pipeassembly is used for heat exchange in which the isocyanate or polyolmaterials flows within a central tube or conduit and a heat exchangefluid flows in another portion of the assembly, preferably disposedradially around the conduit housing the isocyanate or polyol material.An effective amount of thermal insulation is preferably disposed aroundthe exterior or outer periphery of the multiple pipe assembly.

[0127] The polyol component typically contains additives, such asstabilizers, flow modifiers, catalysts, combustion modifiers, blowingagents, fillers, pigments, optical brighteners, and release agents tomodify physical characteristics of the cover Inside the mix head 1216,injector nozzles impinge the isocyanate and polyol at ultra-highvelocity to provide excellent mixing. Additional mixing preferably isconducted using an after-mixer 1230, which typically is constructedinside the mold between the mix head and the mold cavity.

[0128] As is shown in FIG. 21, the mold 1220 includes a golf ball cavitychamber 1232 in which a spherical golf ball mold 1234 with a dimpled,spherical mold cavity 1236 defined. Preferably, an effective amount of amold release agent is applied to the molding surfaces of the moldingchamber. The aftermixer 1230 can be a peanut aftermixer, as in shown inFIG. 5, or in some cases another suitable type, such as a heart, harp ordipper. An overflow channel 1238 or “dump well” receives overflowmaterial from the golf ball mold 1234 through a shallow vent 1242.Heating/cooling passages 1226 and 1240, which preferably are in aparallel flow arrangement, carry heat transfer fluids such as water,oil, etc. through the top mold 1222 and the bottom mold 1224. Injectionmay be performed at various pressures, but it is preferred that thepressure at which each of the components is introduced to the moldingassembly is approximately equal. Preferably, impingement pressures for aRIM process using an isocyanate and a polyol component are about 150 toabout 195 bar, and preferably about 180 bar (all pressures are gauge,i.e. above atmospheric, unless noted otherwise). For the RIM processesdescribed herein, mold cycle times may range from about 30 seconds to upto 5 minutes or more depending upon the properties of the reactants. Fora RIM system using a polyol and an isocyanate as described herein, a 60second molding cycle time has been achieved, and is preferred.

[0129] After molding, the golf balls produced may undergo variousfurther processing steps such as buffing, trimming, milling, tumbling,painting and marking as disclosed in U.S. Pat. No. 4,911,451, hereinincorporated by reference.

[0130] In performing a RIM operation in which polyurethane covers orother golf ball components are formed, it is preferred to use a PSM 90unit available from Isotherm, AG. The PSM 90 unit is used for processingof elastomers and foamed polyurethane and polyureas. Generally, thepolyol and isocyanate components are metered into the PSM 90 and atleast partially mixed under high pressure. Depending upon the mixinghead used, a wide array of different molding strategies can be used.Additionally, a design guide for after-mixers is provided by BayerCorporation under the designation “Engineering Polymers, RIM Part andMold Design, Polyurethanes, a Design Guide,” No. PU-CA007, pp. 52-53 and58, 1995, herein incorporated by reference.

[0131] The resulting golf ball is produced more efficiently and lessexpensively than balls of the prior art. Additionally, the golf balls ofthe present invention may have multiple cover layers, some of them verythin (less than 0.03 inches, more preferably less than 0.02 inches, evenmore preferably less than 0.01 inches) if desired, to produce golf ballshaving specific performance characteristics. For example, golf ballshaving softer outer cover layer(s) and harder inner cover layer(s) maybe produced. Alternatively, golf balls having harder outer coverlayer(s) and softer inner cover layer(s) may be produced. Moreover, golfballs having inner and out cover layers with similar hardnesses are alsoanticipated by the present invention.

[0132] For golf balls have three or more layers, the hardness of thelayers may be varied alternately, such as hard-soft-hard, orsoft-hard-soft, and the like, or golf balls with a cover having ahardness gradient may be produced. The hardness gradient may start withhard inner layers close to the core and get softer at the outer layer,or vice versa. This allows a lot of flexibility and control of finishedgolf ball properties. As previously described, the layers may be of thesame or different materials, and of the same or different thicknesses.

[0133] Specifically, the golf ball of the present invention is notparticularly limited with respect to its structure and construction. Byusing well known ball materials and conventional manufacturingprocesses, the balls may be manufactured as solid golf balls includingone-piece golf balls, two-piece golf balls, and multi-piece golf ballswith three or more layers and wound golf balls. Furthermore, although aRIM process has been described for forming the various gold balls,cores, intermediate ball assemblies, cover layers, and componentsthereof, it will be appreciated that other techniques may be used, suchas, but not limited to, injection molding, compression molding, castmolding, and other processes known in the art.

[0134] The foregoing description is, at present, considered to be thepreferred embodiments of the present invention. However, it iscontemplated that various changes and modifications apparent to thoseskilled in the art, may be made without departing from the presentinvention. Therefore, the foregoing description is intended to cover allsuch changes and modifications encompassed within the spirit and scopeof the present invention, including all equivalent aspects.

Having thus described the invention, we claim:
 1. A golf ball having aplurality of deep dimples defined along an outer surface of said golfball, said golf ball comprising: a core; and a cover layer disposedabout said core, said cover layer having an outer surface and athickness and defining a plurality of dimples along said outer surface,wherein at least 5% of said dimples have a depth greater than saidthickness of said cover layer and extend through said cover layer. 2.The golf ball of claim 1, wherein at least 10% of said dimples have adepth greater than said thickness of said cover layer.
 3. The golf ballof claim 1, wherein at least 20% of said dimples have a depth greaterthan said thickness of said cover layer.
 4. The golf ball of claim 1,wherein at least 30% of said dimples have a depth greater than saidthickness of said cover layer.
 5. The golf ball of claim 1, wherein atleast 40% of said dimples have a depth greater than said thickness ofsaid cover layer.
 6. The golf ball of claim 1, wherein at least 50% ofsaid dimples have a depth greater than said thickness of said coverlayer.
 7. The golf ball of claim 1, wherein at least 60% of said dimpleshave a depth greater than said thickness of said cover layer.
 8. Thegolf ball of claim 1, wherein at least 70% of said dimples have a depthgreater than said thickness of said cover layer.
 9. The golf ball ofclaim 1, wherein at least 80% of said dimples have a depth greater thansaid thickness of said cover layer.
 10. The golf ball of claim 1,wherein at least 90% of said dimples have a depth greater than saidthickness of said cover layer.
 11. The golf ball of claim 1, wherein allof said dimples have a depth greater than said thickness of said coverlayer.
 12. A golf ball comprising: a core; and a cover layer disposedabout said core, said cover layer having a thickness and defining atleast two populations of dimples along an outer surface of said coverlayer, wherein a first population of dimples includes dimples having adepth greater than said thickness of said cover layer and a secondpopulation of dimples includes dimples having a depth less than saidthickness of said cover layer, said first population constituting atleast a minority proportion of the total number of dimples defined alongsaid outer surface of said cover layer.
 13. The golf ball of claim 12,wherein said first population constitutes about half of the total numberof dimples defined along said outer surface of said cover layer.
 14. Thegolf ball of claim 12, wherein said first population constitutes amajority of the total number of dimples defined along said outer surfaceof said cover layer.
 15. The golf ball of claim 12, wherein said coverlayer defines three populations of dimples.
 16. The golf ball of claim12, wherein said cover layer defines four populations of dimples. 17.The golf ball of claim 12, wherein said cover layer defines fivepopulations of dimples.
 18. The golf ball of claim 12, wherein saidcover layer defines six populations of dimples.
 19. The golf ball ofclaim 12, wherein said cover layer is formed via reaction injectionmolding.
 20. A molding apparatus for forming a golf ball having a coverwith a thickness and a plurality of dimples along its outer surface,said molding apparatus comprising: a first molding component defining ahemispherical first mold surface, said first mold surface having atleast two populations of outwardly extending projections that form saiddimples, said populations differing from each other by the height ofsaid projections; a second molding component defining a hemisphericalsecond mold surface, said second mold surface having at least twopopulations of outwardly extending projections that form said dimples,said populations differing from each other by the height of saidprojections, said second molding component adapted such that uponengagement with said first molding component, a generally sphericalmolding chamber results from said first mold surface and said secondmold surface; and provisions for receiving one or more flowablematerials used for forming said golf ball and administering suchmaterials into said molding chamber; wherein said at least onepopulation of outwardly extending projections of said first mold surfaceand said at least one population of outwardly extending projections ofsaid second mold surface have a projection height in the range of fromabout 0.005 inches to about 0.050 inches.
 21. The golf ball produced bythe apparatus of claim
 20. 22. The molding apparatus of claim 20,wherein the total number of projections of said first population andsaid second population along said first mold surface and said secondmold surface is a minority proportion of the total number of projectionsalong said first mold surface and said second mold surface.
 23. Themolding apparatus of claim 20, wherein the total number of projectionsof said first population and said second population along said firstmold surface and said second mold surface is a majority proportion ofthe total number of projections along said first mold surface and saidsecond mold surface.
 24. A reaction injection molding apparatus forforming a golf ball core or intermediate ball assembly and an outercover layer disposed about said core or ball assembly, said moldingapparatus comprising: a first mold defining a hemispherical first moldsurface; a second mold defining a hemispherical second mold surface,said first and said second mold surfaces having a first population ofraised regions that form dimples along said cover layer, and a secondpopulation of raised regions each having a height greater than thethickness of said outer cover layer; provisions for receiving two ormore flowable reactants utilized for forming said outer cover layer;wherein said second population of raised regions constitutes a minorityproportion of the total number of dimples along said cover layer.
 25. Agolf ball produced by the molding apparatus of claim
 24. 26. The moldingapparatus of claim 24, wherein said second population of raised regionsconstitutes at least 5% of the total number of dimples along said coverlayer.
 27. A process for producing a golf ball having a particularproportion of deep dimples along an outer surface of said ball, saidprocess comprising: providing a molding apparatus that defines agenerally spherical molding chamber resulting from a molding surfacehaving a first population of raised regions that form dimples in a golfball, and a second population of raised regions that form deep dimplesin a golf ball, providing a flowable molding material; positioning acore or intermediate ball assembly in said molding chamber; introducingsaid flowable molding material into molding chamber between said core orintermediate ball assembly and said molding surface; and hardening saidflowable molding material to thereby form said golf ball; wherein saidsecond population of said raised regions constitutes at least 5% of thetotal number of dimples along said outer surface of said ball.
 28. Agolf ball produced by the process of claim
 27. 29. The process of claim2 wherein said second population of said raised regions constitutes atleast about 5% of the total number of dimples along said outer surfaceof said ball.